Answer:
D 2 million years is the answer
Explanation:
B
Every living thing makes energy through respiration and plants use solar energy during respiration.
He is making a plant cell since the cell walls are box shaped, the balloon would be the large vacuole which takes up a lot of space in the cell, the marbles would be the ribosomes.
Answer:
Long tail and narrow head.
Explanation:
A sperm cell is adapted to reduce friction as it swims by having long head, narrow tail and enzymes. These features of sperm provides ability to swim straight to the egg cell. Long tail helps the sperm cell to swim towards the egg cell, narrow head of sperm cell make the sperm cell for faster swimming towards the egg cell and enzymes present in the head of the sperm helps break through the egg cell membrane so we can say that the long tail and narrow head of sperm cells helps in faster swimming.